A HUMAN PERSPECTIVE Akierou Awe lives in a mud-brick house inNigeria’s Niger delta, a region that contains most of Nigeria’s oil. On themorning of July 10, 2000, Awe’s four sons had been collecting fuel froma leaking pipeline to help scrape out a living in this poverty-strickenregion. They hoped to resell the fuel for more than the going rate of 21cents a quart. Suddenly, an explosion shook the area, and a fire spreadalong a mile-long stretch of the pipeline. The blast killed more than 300people, including three of Awe’s sons. This accident is one of many inthe recent past that have claimed the lives of hundreds of Nigerians.Nigeria has become one of the top oil producers in the world, but at thecost of thousands of lives and major environmental ruin in the region.

Desertification of the SahelSahel means “shore of the desert” in Arabic. You can see from the physi-cal map on page 403 that the Sahel is a narrow band of dry grassland thatruns east to west along the southern edge of the Sahara. People use theSahel for farming and herding. Since the 1960s, the desert has spread intothe Sahel. This shift of the desert is called desertification. Desertificationis an expansion of dry conditions into moist areas that are next to deserts.Normally, it results from nature’s long-term cycle, but as you can see inthe illustration below, human activity is speeding up the process.

HUMAN CAUSES OF DESERTIFICATION Geographers and other scien-tists have identified several human activities that increase the pace of desertification. For example, allowing overgrazing of vegetation by

Human–EnvironmentInteraction

Main Ideas• The Sahara’s expansion is

causing problems for Africa’s

farmers.

• The Nigerian oil industry has

caused serious environmental

damage in the Niger delta.

Places & TermsNiger delta

Sahel

desertification

Aswan High Dam

silt

Connect to the Issues

colonialism European

colonialism has caused

political, economic, and

environmental problems

in Africa today.

The Sahel receives little rainfall. The vegetation lives

in a fragile state, having barely enough water and

food to survive.

1 2 Farming, overgrazing by livestock, and

burning wood for fuel all contribute to

desertification.

424

425

AFR

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livestock exposes the soil. Animals also trample the soil, making it morevulnerable to erosion.

Farming also increases the pace of desertification. When farmersclear the land to plant crops, they expose the soil to wind, which cancause erosion. In addition, when farmers drill for water to irrigatecrops, they put further stress on the Sahel. Widespread drilling andmore irrigation increase salt levels in the soil, which prevent the growthof vegetation.

Increasing population levels are an indirect cause of desertification.More people require more food. As a result, farmers continue to clearmore land for crops, burn more wood for fuel, and overfarm the land theyalready have.

RESULTS OF DESERTIFICATION Desertification has affected manyparts of Africa. For example, large forests once existed aroundKhartoum, Sudan. In addition, desertification is slowly destroying atropical rain forest around Lake Chad in the southern edge of the Sahel.Slowing desertification is difficult. Some African countries haveincreased tree planting and promoted more efficient use of forests andfarmland in hopes of slowing the process.

Harming the Environment in NigeriaAnother environmental issue concerns the discovery of oil in Nigeria in1956. Rich oil deposits in the Niger delta made Nigeria one of Africa’swealthiest countries. However, in drilling for oil, the Nigerian govern-ment and foreign oil companies have often damaged the land andharmed the people living in the Niger delta.

A MAJOR OIL PRODUCER Nigeria is the sixth leading oil exporter inthe world. Two million barrels are extracted each day, much of it shippedto the United States. Oil accounts for 80 to 90 percent of Nigeria’s income.

During the 1970s, high oil prices made Nigeria one of the wealthiestnations in Africa. As a result, the government borrowed heavily againstthe future sale of its oil. However, oil prices eventually fell, and theNigerian government owed millions of dollars to other nations, includ-ing the United States. Mismanagement, poor planning, corruption, anda decline in oil prices left Nigeria poorer than before the oil boom.

3 4During desertification, dry grasses die and are

replaced by tougher plants like shrubs. These

plants do not cover the soil as well as grass.

With less vegetation covering the soil, any

rain that falls evaporates quickly. Over the

years, the wind then blows the dry soil into

a desert-like state.

Using the AtlasRefer to the

physical map on

page 403. What

countries are

probably most

affected by

desertification

of the Sahel?

426 CHAPTER 18

DESTROYING THE LAND AND PEOPLE The damage caused by oilcompanies and the Nigerian government has been severe. More than4,000 oil spills have occurred in the Niger delta over the past fourdecades. Cleanup operations have been slow and sometimes non-exis-tent. Fires often resulted, causing acid rain and massive deposits of soot,and people in the region contracted respiratory diseases. In addition,between 1998 and 2000, oil pipeline explosions killed more than 2,000people—including three of Akierou Awe’s sons.

Many of these explosions were notaccidents but were caused intentionally.Bandits, in cooperation with corruptgovernment officials and the military,drain fuel from the pipelines and thenresell it. In 1999, these bandits damagedabout 500 pipelines. Once the banditsfinish draining oil, local villagers arrive.They use small cans to collect anyspilled oil and then sell it.

A NEW START In May 1999, OlusegunObasanjo became Nigeria’s new presi-dent. Although a former Nigerian mili-tary leader himself, he has distancedhimself from the armed forces. He hasstarted many economic reforms andfired corrupt government officials.Now he faces the task of finding waysfor Nigeria to benefit from oil.

Controlling the NileEgypt faces environmental challengescaused by another resource—water.Throughout history, the Egyptianshave tried to control the floodwaters ofthe Nile River. Ancient Egyptians builtcanals and small dams. In spite ofthese efforts, though, the people stillexperienced cycles of floods anddroughts. To solve these problems,Egyptians completed the first AswanDam on the Nile in 1902, which quick-ly became outmoded.

THE ASWAN HIGH DAM Four miles upriver from the first AswanDam, the Egyptians cut a huge channel through the land beside theNile River. The builders used the rocks from the channel as a basefor their new creation—the Aswan High Dam—which was complet-ed in 1970. Lake Nasser, which Egypt shares with Sudan, is the arti-ficial lake created behind the dam. It stretches for nearly 300 miles.

Seeing PatternsWhy did

bandits and cor-

rupt government

officials drain fuel

from the pipelines?

0

0 150 300 kilometers

150 300 miles

Lambert AzimuthalEqual-Area Projection

Flood plain

25°E

25°N

30°N

35°E 40°E

Tropic of Cancer

Mediterranean Sea

Red Sea

AR

AB

IAN

DESERT

NUBIANDESERT

SINAIPEN.

Nile

R .

LakeNasser

First CataractAswan

High Dam

EGYPTLIBYA

SUDAN

Aswan

Asyut

AlexandriaCairo

El Minya

N

S

EW

0

0 150 300 kilometers

150 300 miles

Lambert AzimuthalEqual-Area Projection

Flood plain

HUMAN–ENVIRONMENTINTERACTION The

Aswan High Dam has

helped Egypt control

the flooding of the

Nile River.

What are some ofthe benefits of theAswan High Dam?

Human–Environment Interaction 427

Places & TermsExplain the meaning or

identify the location of

each of the following

terms.

• Niger delta

• Sahel

• desertification

• Aswan High Dam

• silt

Taking Notes HUMAN–ENVIRONMENTINTERACTION Review the notes

you took for this section.

• Which activities illustrate human

control of the environment?

• Which examples illustrate an

environment changed by humans?

Human-Environment

Interaction

Main Ideas a. What are some of the

causes of desertification?

b. How has the discovery of

oil in the Niger delta

affected Nigeria’s

environment?

c. What were some of the

reasons that the Egyptian

government built the

Aswan High Dam?

Geographic ThinkingDrawing Conclusions Do

you think that the benefits of

the Aswan High Dam have

outweighed its problems?

Think about:

• the dam’s effect on Egypt’s

food supply and farmers

See SkillbuilderHandbook, page R5.

ASKING GEOGRAPHIC QUESTIONS Study the map of the Aswan High Dam on page 426.

Write three geographic questions about the map, such as one concerning the location of

the dam. Write a report answering one of your three questions. Then present your findings

to the class.

AFR

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The dam gives farmers a regular supply of water. It holds theNile’s floodwaters, releasing them as needed so that farmers can usethe water effectively for irrigation. As a result of the dam, farmerscan now have two or three harvests per year rather than one.Irrigation canals even keep some fields in continuous productionthrough the use of artificial fertilizers. The dam has increasedEgypt’s farmable land by 50 percent. The dam has also helped Egyptavoid droughts and floods.

PROBLEMS WITH THE DAM Though the dam has provided Egyptwith many benefits, it has also created some problems. During thedam’s construction, many people had to be relocated, includingthousands of Nubians, whose way of life was permanently changed.In addition, one of ancient Egypt’s treasures, the temples at AbuSimbel, had to be moved. Other smaller ancient treasures could notbe saved and now lie at the bottom of Lake Nasser.

The dam also decreased the fertility of the soil around the Nile.First, the river no longer deposits its rich silt, or sediment, on thefarmland. Farmers must now rely on expensive artificial fertilizersto enrich the soil. Second, this year-round irrigation has resulted ina rising water table in Egypt. As a result, salts from deep in the earthhave decreased the fertility of the soil. Before the dam was built,floodwaters flushed out the salt. Now expensive field drains have tobe installed.

Rates of malaria and other diseases have increased due to greaternumbers of mosquitos, which thrive in the still waters of LakeNasser and the irrigation canals. Furthermore, because Lake Nasserholds the floodwaters, Egyptians lose millions of gallons of freshwater every year to evaporation. Measuring the success of theAswan High Dam is difficult. For all the ways it has helpedEgyptians, it has also created new problems.

Background

The channel next

to the Aswan

High Dam pro-

duces about 40

percent of Egypt’s

electricity, and

Lake Nasser sup-

ports commercial

fishing.

Seeing PatternsHow do

farmers fertilize

their land now

that the dam traps

all the silt?